When I hear cutting the deck it sounds like the vinyl liner may not be a cost effective option either? I was hoping this was a viable option at less than $10k. If we do this then we can't simply decide 5 years down the road to ditch the liner and go with a more expensive option because of the work that was done to customize beneath decking, or is that not a concern afterwards just something that has to be done now?
You can replaster the concrete but you can't put a vinyl liner over just the walls. There is not a way to attach the vinyl at the top of the wall or at the bottom of the wall and create a water proof seal.
The next best option is to put a vinyl liner in. To do this you will have to install some sort of bead receiver at the top of the wall. You will have to cut concrete deck and dig down to install vinyl liner returns. Your main drain won't be usable unless it is a vinyl main drain to begin with.